JP2006208024A - Remaining amount display system and remaining amount display method - Google Patents

Abstract

In a large-capacity fuel tank, the remaining amount can be appropriately displayed by an inexpensive means over the entire range from a full state to an empty state, and the remaining amount is low. Provided is a fuel remaining amount display system capable of accurately performing a remaining amount display in a quantity region.
According to the present invention, there is provided a remaining amount display system for measuring and displaying a remaining amount of fuel in a large capacity type fuel tank, wherein the remaining amount in the fuel tank is equal to or less than a predetermined reference amount. A float sensor that measures the remaining amount in the range, at least one float switch that detects the remaining amount in the range where the remaining amount in the fuel tank exceeds the reference amount, and the remaining amount obtained by the float sensor There is provided a remaining amount display system comprising: a sensor remaining amount display portion that performs display and a switch remaining amount display portion that displays a remaining amount obtained by the float switch.
[Selection] Figure 1

Description

  The present invention relates to a remaining amount display system and a remaining amount display method for measuring and displaying the remaining amount of fuel in a fuel tank that contains fuel, and is particularly used for a working machine such as a hydraulic excavator. The present invention relates to a remaining amount display system and a remaining amount display method that can appropriately display the remaining amount of fuel from a full state (Full) to an empty state (Empty) in a large-capacity fuel tank.

  Conventionally, vehicles and work machines have been equipped with a fuel tank that contains fuel such as gasoline, and a driver's seat has a remaining amount indicator that displays the remaining amount of fuel contained in the fuel tank. is set up. Thereby, the driver grasps the degree of fuel decrease by checking the remaining amount of fuel displayed on the remaining amount display meter, and determines the timing of refueling.

  In general, as a method of measuring the remaining amount of fuel in the fuel tank, a method using a float sensor as described in, for example, Japanese Patent Application Laid-Open No. 2004-325081 (Patent Document 1) is known. For example, as shown in FIG. 4, the float sensor 20 includes a variable resistor 21, an arm 22 that is supported by the variable resistor 21 so as to be rotatable up and down, and a float 23 that is attached to the tip of the arm 22. . The float sensor 20 detects the fuel level from the vertical movement position of the float 23 and measures the remaining amount in the fuel tank.

  Specifically, the position of the float 23 that moves up and down according to the increase and decrease of the liquid level is detected by the amount of rotation of the arm 22 that supports the float 23, and the variable resistor 21 of the variable resistor 21 is detected according to the amount of rotation of the arm 22. The resistance value changes. The change in the resistance value of the variable resistor 21 is output to a remaining amount calculating means such as a controller (not shown). The remaining amount calculating means calculates the remaining amount of fuel in the fuel tank from the input resistance value of the variable resistor 21. Is done. Thereafter, the calculation result of the remaining amount calculating means is output to a remaining amount display meter installed in the driver's seat, and the remaining amount is displayed on the remaining amount display meter.

  Further, for example, in Japanese Patent Application Laid-Open No. 2003-136879 (Patent Document 2), in a working machine such as a hydraulic excavator, a float sensor is used to determine the total remaining amount of both fuel tanks when two fuel tanks are installed at different heights. A fuel tank structure that can be used and displayed accurately is disclosed. In the fuel tank structure described in Patent Document 2, two fuel tanks are connected via a communication pipe, so that fuel can flow in and out between the two fuel tanks. Further, float sensors are attached to the two fuel tanks, respectively, and these float sensors are installed at different height positions in the vertical direction. Furthermore, the electric circuits of both float sensors are connected in series. In the fuel tank structure described in Patent Document 2, the capacity of the fuel that can be accommodated can be increased by providing two fuel tanks. Further, by detecting the resistance values of both float sensors connected in series with an electric circuit, the total of the remaining amounts stored in the two fuel tanks can be displayed almost accurately on the remaining amount display meter.

  Furthermore, for example, Japanese Patent Application Laid-Open No. 10-77872 (Patent Document 3) and Japanese Patent Application Laid-Open No. 10-83467 (Patent Document 4) disclose an apparatus for predicting the operating time of a work machine. For example, in the operable time predicting device described in Patent Document 3, first, the remaining amount in the fuel tank is measured every predetermined time by using a fuel level meter such as the float sensor as described above, and the engine speed and the like are measured. Based on the above, the fuel consumption is calculated. The calculated fuel remaining amount is calculated by subtracting the calculated fuel consumption from the measured remaining amount in the fuel tank. At the same time, the fuel consumption per hour estimated from the consumption per predetermined time is obtained. The calculated remaining amount in the fuel tank is divided by the fuel consumption per hour obtained by the calculation, thereby obtaining the operable time of the work machine.

  By using the operation time prediction device disclosed in Patent Document 3 as described above and the operation time prediction device described in Patent Document 4, it is possible to accurately predict how many hours the work machine can be operated. Can be displayed and rational refueling can be performed.

In the techniques described in these Patent Documents 1 to 4, a float sensor that mainly measures the displacement of the liquid level of the fuel is used in order to obtain the remaining amount of the fuel stored in the fuel tank. . On the other hand, as means for measuring the remaining amount of the fuel tank without using the float sensor, the distance to the liquid surface is measured using ultrasonic waves or laser light as exemplified in Patent Documents 3 and 4, for example. There is also a way to find out.
JP 2004-325081 A JP 2003-136879 A Japanese Patent Laid-Open No. 10-77872 Japanese Patent Laid-Open No. 10-83467

  In recent working machines such as hydraulic excavators, the size of the fuel tank has been increased from the viewpoint of increasing the size of the working machine itself, improving maintainability and working efficiency. For example, the capacity has increased to 2000 liters (hereinafter referred to as “L” as “L”). In addition, large-capacity fuel tanks exceeding 3000L have been put into practical use. Even in such a large-capacity fuel tank, the float sensor used in Patent Documents 1 to 4 and the like is mainly used as means for measuring the remaining amount of fuel contained therein.

  However, in the conventional float sensor, the measurable range that can be measured by one float sensor varies depending on the cross-sectional area of the fuel tank, but is about 1200 to 1300 L at the maximum. Amount. Therefore, in the large-capacity fuel tank as described above, the remaining amount in the fuel tank is measured in all states from a full tank state to an empty state using one float sensor. I couldn't.

  For this reason, in a conventional large-capacity fuel tank, for example, a float sensor is disposed below the fuel tank, and the remaining amount is measured only in the low remaining amount region. On the other hand, in the remaining amount area on the upper side exceeding the measurement range of the float sensor, the remaining amount is not basically measured, and the remaining amount display instrument always displays “Full”.

  Therefore, in the conventional fuel remaining amount display, the full state is displayed for a long time until the remaining amount in the fuel tank decreases to the measurement range of the float sensor. When the remaining amount decreases to the measurement range of the float sensor, the display of the full state is switched to the display of the remaining amount measured by the float sensor, and the remaining amount measured by the float sensor is accurately displayed on the remaining amount display meter. Become so. However, in this case, the full state is displayed on the remaining amount display instrument for a long time, but the time from the start of displaying the remaining amount measured by the float sensor until the display of the Empty state is shortened. . In particular, in the case of a work machine with a large amount of fuel consumption such as a hydraulic excavator, there is a problem that the Empty state is displayed in a short time.

  Therefore, the driver operating the work machine can accurately display the remaining amount in the fuel tank from the full tank to the empty state, and can easily grasp the remaining state of the fuel tank. It has been desired that the increase / decrease in the remaining amount displayed on the remaining amount display meter is displayed smoothly.

  As a method for solving the problem in the large-capacity fuel tank as described above, for example, it is conceivable to measure the remaining amount of the large-capacity fuel tank using a large float sensor having a wide measurement range. However, when the remaining amount is measured using a large float sensor with a wide measurement range, there is a problem that the measurement error is very large and the reliability is poor. Therefore, for example, when an error occurs in the remaining amount display in the low remaining amount region of the fuel tank, it becomes impossible to supply the fuel tank at an appropriate time. For this reason, the work machine runs out of fuel and is forced to stop the work, and conversely, although fuel remains in the fuel tank, the fuel is replenished to the fuel tank. There has also been a problem that the number of replenishment times has increased more than necessary and hindered the work efficiency.

  In addition, as a method for accurately measuring the remaining amount of a large-capacity fuel tank and expanding the remaining amount measurement range, for example, a plurality of conventionally used float sensors are arranged in the vertical direction of the fuel tank. However, it is conceivable to continuously measure the displacement of the fuel level with a plurality of float sensors. However, in this case, since a plurality of float sensors are required, there is a problem that the cost is increased.

  As another method, for example, as illustrated in Patent Documents 3 and 4 above, by measuring the distance to the fuel level using ultrasonic waves or laser light, a large-capacity fuel tank A method of accurately measuring the remaining amount in a wide range is also conceivable. However, in this case as well, there is a problem that the cost of equipment such as ultrasonic waves and laser light becomes high and is not suitable for practical use.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to cover the entire capacity of a large-capacity fuel tank from a full tank state to an empty state. The remaining amount can be displayed appropriately by inexpensive means, and the remaining amount can be accurately displayed in the low remaining amount region, and the change in the remaining amount can be displayed smoothly throughout. The present invention provides a fuel remaining amount display system and a remaining amount display method.

  In order to achieve the above object, a remaining amount display system of the present invention is a remaining amount display system that measures and displays the remaining amount of fuel in a large-capacity fuel tank. A float sensor for measuring a remaining amount in a range where the amount is equal to or less than a predetermined reference amount; at least one float switch for detecting a remaining amount in a range where the remaining amount in the fuel tank exceeds the reference amount; The main feature is that it comprises a sensor remaining amount display unit for displaying the remaining amount obtained by the float sensor and a display means having a switch remaining amount display unit for displaying the remaining amount obtained by the float switch. Is.

  In the remaining amount display system of the present invention, it is preferable that the float switch is provided in multiple stages at different height positions of the fuel tank and detects the remaining amount in the fuel tank in multiple stages.

  Further, in the remaining amount display system, calculation is started when a detection signal from the float switch is received, and a consumption calculation for calculating the consumption of fuel in the fuel tank with the passage of time after receiving the detection signal. And a remaining amount calculation unit that calculates a remaining amount in the fuel tank by subtracting a consumption amount calculated by the consumption amount calculation unit from a remaining amount when detected by the float switch It is preferable that a remaining amount in the fuel tank obtained by the remaining fuel amount calculating means is continuously displayed on a switch remaining amount display portion of the display means.

  In this case, an engine controller that controls the fuel injection amount of the engine that consumes the fuel in the fuel tank is provided, and the consumption amount calculation unit is configured to perform the operation based on the fuel injection amount data output from the engine controller. It is desirable to calculate consumption.

  Further, in the remaining amount display system of the present invention, it is preferable that the display means outputs an alarm when the remaining amount in the fuel tank becomes a predetermined warning amount or less.

  Next, a remaining amount display method according to the present invention is a remaining amount display method for measuring and displaying the remaining amount of fuel in a large-capacity fuel tank, wherein the remaining amount in the fuel tank is a predetermined amount. Detecting a remaining amount with at least one float switch when the amount is greater than a reference amount; measuring a remaining amount with a float sensor when the remaining amount in the fuel tank is less than or equal to the reference amount; and And the remaining amount obtained by the float sensor is displayed on the display means.

  Such a remaining amount display method of the present invention includes detecting the remaining amount in the fuel tank in multiple stages by the float switches provided in multiple stages at different height positions of the fuel tank. It is preferable.

  In the remaining amount display method, the calculation is started when the detection signal from the float switch is received, and the consumption of fuel in the fuel tank with the passage of time after receiving the detection signal is calculated by the calculation. Calculating the remaining amount in the fuel tank by subtracting the calculated consumption amount from the remaining amount detected by the float switch, and displaying the calculated remaining amount in the fuel tank in the display means It is preferable that the display comprises continuous display.

  A fuel remaining amount display system according to the present invention includes a float sensor that measures a remaining amount in a range that is less than or equal to a predetermined reference amount in a fuel tank, and at least one that detects a remaining amount in a range that exceeds a predetermined reference amount. A float switch and display means for displaying the remaining amount obtained from the float sensor and the float switch are provided. As a result, when the remaining amount in the fuel tank is below the reference amount, the remaining amount can be measured continuously and accurately by the float sensor, while the remaining amount in the fuel tank exceeds the predetermined reference amount. Then, the remaining amount can be reliably detected at the position where the float switch is disposed. In the above display means, when the remaining amount exceeds the reference amount, the remaining amount obtained by the float switch can be displayed on the switch remaining amount display portion, and when the remaining amount is less than the reference amount, the remaining amount obtained from the float sensor is displayed. Since it can be displayed on the sensor remaining amount display section, the remaining amount in the fuel tank can be appropriately displayed in all states from a full tank state to an empty state. Further, the remaining amount display of this display means is highly reliable because the remaining amount obtained by the float sensor and the float switch is displayed, and the low amount measured by the float sensor whose remaining amount is below the reference amount. In the remaining amount area, the remaining amount can be displayed very accurately.

  In the present invention, the predetermined reference amount can be measured when the float sensor is arranged so that the remaining amount can be measured in a low remaining amount region including an empty state. The upper limit of the remaining amount range is shown.

  In the present invention, the float switch is provided in multiple stages at different height positions of the fuel tank, so that the remaining amount in the fuel tank can be detected in multiple stages. Thereby, when the remaining amount in the fuel tank exceeds the reference amount, a change in the remaining amount can be detected in stages, and the display unit can display the remaining amount detected by each float switch.

  Furthermore, in the present invention, a consumption calculation unit that calculates the consumption of fuel in the fuel tank over time after receiving a detection signal from the float switch, and a consumption calculation from the remaining amount detected by the float switch A fuel remaining amount calculating means having a remaining amount calculating section for calculating the remaining amount in the fuel tank by subtracting the consumption calculated by the fuel tank, The remaining amount can be continuously displayed on the display means. Thus, in the range where the remaining amount in the fuel tank exceeds the reference amount, the remaining amount in the range that is not detected by the float switch can be obtained by interpolation with the remaining fuel amount calculating means. Further, by displaying the remaining amount calculated by the remaining fuel amount calculating means on the display means, it is possible to continuously and smoothly display the change in the remaining amount in the range exceeding the reference amount on the display means.

  In this case, an engine controller for controlling the fuel injection amount of the engine can be provided, and the consumption amount calculation unit can calculate the consumption amount based on the fuel injection amount data output from the engine controller. . In this way, by using the consumption calculated based on the fuel injection amount of the engine, the remaining amount in the fuel tank can be accurately calculated by the remaining amount calculating unit of the remaining fuel calculating unit, and the display unit The remaining amount display is also more reliable.

  Further, according to the present invention, the display means can output an alarm when the remaining amount in the fuel tank falls below a predetermined warning amount. With this output alarm, the driver can surely know that the remaining amount in the fuel tank is about to run out and rationally refuel before the work machine stops operating due to running out of fuel. be able to.

  Next, in the remaining amount display method according to the present invention, when the remaining amount in the fuel tank is equal to or greater than a predetermined reference amount, the remaining amount is detected by at least one float switch, and the remaining amount in the fuel tank is predetermined. It includes measuring the remaining amount with the float sensor when the reference amount is below the reference amount, and displaying the remaining amount obtained by the float switch and the remaining amount obtained by the float sensor on the display means.

  As a result, when the remaining amount in the fuel tank is within a predetermined reference amount, the remaining amount can be accurately measured by the float sensor, and at least when the remaining amount in the fuel tank is greater than the predetermined reference amount, With one float switch, the remaining amount can be reliably detected at the position where the float switch is disposed. Further, by displaying the remaining amount in the fuel tank obtained from the float sensor and the float switch on the display means, the display means appropriately displays the remaining amount in the fuel tank from a full tank state to an empty state. Can be displayed. In particular, in the low remaining amount region where the remaining amount is equal to or less than the reference amount, the remaining amount can be accurately displayed.

  Moreover, the remaining amount display method of the present invention can detect the remaining amount in the fuel tank in multiple stages by using float switches provided in multiple stages at different height positions of the fuel tank. As a result, when the remaining amount in the fuel tank exceeds the reference amount, changes in the remaining amount can be detected in stages with the float switch provided in multiple stages, and the remaining amount can be displayed more accurately on the display means. Can do.

  Furthermore, in the present invention, when a detection signal is received by the float switch, the consumption of fuel in the fuel tank is calculated as time passes after receiving this detection signal, and the consumption calculated from the remaining amount detected by the float switch is calculated. The remaining amount in the fuel tank can be calculated by subtracting the amount, and the calculated remaining amount in the fuel tank can be continuously displayed on the display means. As a result, the remaining amount in the range not detected by the float switch can be obtained by interpolation by the remaining fuel amount calculating means, and can be displayed continuously and smoothly by the display means.

  Hereinafter, preferred embodiments of the present invention will be described in detail. FIG. 1 is a schematic diagram schematically showing a configuration of a fuel remaining amount display system according to the present invention, and FIG. 2 is a diagram schematically showing an example of a specific mode of a display means.

  The fuel remaining amount display system according to the present invention measures and displays the remaining amount in a large-capacity type fuel tank having a capacity of 2000L, more than 3000L, which is applied to a work machine such as a hydraulic excavator. This is a remaining amount display system. As an example, FIG. 1 shows a configuration of a remaining amount display system that measures and displays the remaining amount of a fuel tank having a maximum fuel capacity of 3200L.

  A remaining amount display system 1 shown in FIG. 1 includes a float sensor 4 that measures the remaining amount of fuel 3 contained in a large-capacity fuel tank 2 in a range where the remaining amount of fuel 3 is not more than a predetermined reference amount. First, second, and third float switches 5, 6, and 7 that detect the remaining amount in a range where the remaining amount exceeds a predetermined reference amount, and the remaining amount obtained by the float sensor 4 and the float switches 5 and 6 , 7 and display means 10 serving as a remaining amount display meter for displaying the remaining amount obtained.

  Here, the reference amount is a value that is the upper limit of the remaining amount measurable range in the float sensor 4. The value of the reference amount varies depending on the size of the fuel tank and the measurement capability of the float sensor. For example, for a fuel tank having a size that the maximum capacity of fuel disposed in a hydraulic excavator exceeds 3000L, for example, When the largest float sensor in practical use is used, the upper limit of the range in which the remaining amount of the float sensor can be measured is about 1200 to 1300L. In the present embodiment, a case will be described in which the float sensor 4 has a maximum remaining capacity measurement range of 1280 L for a fuel tank with a maximum capacity of 3200 L, and the reference amount value is 1280 L. The float sensor 4 is not limited to a float sensor that can measure the remaining amount as described above within a range of 1280 L.

  As such a float sensor 4, what is generally used conventionally can be used. For example, as shown in FIG. 1, a variable resistor 11, an arm 12 supported by the variable resistor 11 so as to be pivotable up and down, and a float 13 attached to the tip of the arm 12, a liquid of the fuel 3 What detects a surface level by the vertical movement position of the float 13 can be used. Further, in the present embodiment, the float sensor 4 is installed at a predetermined height position below the fuel tank so that the remaining amount can be measured in the low remaining amount region equal to or less than the reference amount (1280 L) in the fuel tank 2. .

  Further, the first to third float switches 5, 6, 7 for detecting the remaining amount in the fuel tank are provided in three stages at different height positions in the range exceeding 1280 L in the fuel tank 2. These float switches 5, 6 and 7 detect the remaining amount of fuel by performing ON / OFF operation of the switch in accordance with the level of the fuel contained in the fuel tank. Float switches such as those used in can be used.

  Accordingly, the first to third float switches 5, 6 and 7 are respectively installed at different height positions of the fuel tank, and by checking the change of the float switch from ON to OFF at the height positions, the fuel Can be accurately obtained at each point where the first to third float switches 5, 6 and 7 are installed.

  For example, in the fuel tank having a maximum capacity of 3200L shown in FIG. 1, the first float switch is installed at a position where the remaining amount of 2800L can be detected, and the second and third float switches 6 and 7 are respectively It is installed at a position where the remaining amount of 2300L and 1800L can be detected. By providing the float switch in three stages in this way, the remaining amount in the fuel tank can be detected in stages at each point of 2800L, 2300L, and 1800L. In the present embodiment, the case where three float switches are arranged at equal intervals has been described. However, the present invention is not limited to this, and the installation interval of each float switch can be changed as appropriate. is there.

  In the remaining amount display system of the present embodiment, the float sensor 4 outputs the measured remaining amount data, and the first to third float switches 5, 6, and 7 detect the remaining amount data. Can be output respectively. The remaining amount data output from the float sensor 4 and the first to third float switches 5, 6, and 7 are input to the remaining fuel amount calculation means 8.

  The remaining fuel amount calculation means 8 starts the calculation when it receives a detection signal from any of the first to third float switches 5, 6 and 7, and the fuel with the passage of time after receiving the detection signal. By subtracting the consumption calculated by the consumption calculator from the remaining amount detected by the float switch that outputs the detection signal and the consumption calculator that calculates the consumption of fuel in the tank, A remaining amount calculating unit for calculating the remaining amount.

  In this case, for example, as shown in FIG. 1, the remaining amount display system 1 includes an engine controller 9 that controls the fuel injection amount of the engine that consumes the fuel in the fuel tank 2. This fuel injection amount data can be output, and the output fuel injection amount data can be input to the consumption amount calculation unit of the remaining fuel amount calculation means 8.

  As a result, the consumption amount calculation unit of the remaining fuel amount calculation means 8 detects the remaining amount with any one of the first to third float switches 5, 6, 7 and then the engine fuel input from the engine controller 9. Based on the injection amount data, it is possible to calculate the amount of fuel consumed from the fuel tank as time elapses after the remaining amount is detected by the float switch. Further, the remaining amount calculation unit of the remaining fuel amount calculation means 8 subtracts the fuel consumption amount calculated by the consumption amount calculation unit from the remaining amount data detected by the float switches 5, 6, and 7. The remaining amount in a range that is not detected by the first to third float switches 5, 6, and 7 can be calculated and obtained.

  Further, the remaining fuel amount calculation means 8 is calculated based on the actual remaining amount data obtained by the float sensor 4 and the first to third float switches 5, 6, and 7 and the remaining fuel amount calculation means 8. The remaining amount data can be output to the display means 10.

  In the display means 10, the remaining amount data outputted from the remaining fuel amount calculating means 8 is continuously inputted, and the remaining amount in the fuel tank is displayed to the driver based on the inputted data. Can do. For example, as shown in FIG. 2, the display unit 10 includes a sensor remaining amount display unit that displays the remaining amount measured by the float sensor 4 and the remaining amounts detected by the first to third float switches 5, 6, and 7. A switch remaining amount display unit for displaying the amount and the remaining amount calculated by the fuel remaining amount calculating means 8. The display means 10 displays the remaining amount by indicating the remaining amount on the monitor 15 based on the remaining amount data continuously input from the fuel remaining amount calculating means 8. Digital display.

  Thereby, in the sensor remaining amount display part of the display means 10, the actual remaining amount measured by the float sensor 4 can be continuously displayed, and the change in the remaining amount when the remaining amount is below the reference amount is smoothly displayed. be able to. Further, in the switch remaining amount display portion of the display means 10, when the remaining amount in the fuel tank is detected at each point of 2800L, 2300L and 1800L by the first to third float switches 5, 6 and 7, the needle 16 Can be displayed in accordance with Full, 2300L, and 1800L, respectively. Further, the switch remaining amount display unit continuously displays the calculated remaining amount obtained by the fuel remaining amount calculation means 8 on the switch remaining amount display unit, thereby remaining amount when the remaining amount exceeds the reference amount. Can be displayed smoothly.

  In the present embodiment, the reference amount that is the upper limit of the remaining amount measurement range of the float sensor 4 is 1280 L as described above. On the other hand, in the display means 10 shown in FIG. 2, the scale between the sensor remaining amount display portion and the switch remaining amount display portion is displayed at 1300L. However, the scale of 1300L in the display means 10 is provided to make it easy to understand the remaining amount display for the driver, and is not a numerical value indicating the reference amount. In the display means 10, the position and numerical value of the scale can be changed as appropriate.

  In addition, the display means 10 can output an alarm for notifying the driver that the remaining amount is insufficient when the remaining amount in the fuel tank becomes a predetermined warning amount or less. For example, in a hydraulic excavator or the like, about 180 to 190 L of fuel is required to perform work for about 1 to 2 hours. Therefore, in this embodiment, the warning amount is set to 186 L, for example, and when the remaining amount in the fuel tank becomes 186 L or less, an “Empty” display 17 or the like is displayed as an alarm as shown in FIG. It can be put on the monitor 15.

  Furthermore, in the present embodiment, the fuel remaining amount calculating means 8 is configured to be able to store the remaining amount of fuel stored in the fuel tank at the time when the operation of the work machine is stopped. ing.

  Next, a remaining amount display method for displaying the remaining amount in the large-capacity fuel tank provided in the work machine using the remaining amount display system will be described in detail. Here, FIG. 3 is a flowchart showing an example of the remaining amount display method according to the present invention. In FIG. 3, the float switch is abbreviated as float SW.

  In the remaining amount display method according to the present embodiment, the fuel remaining amount calculation means 8 performs the present operation immediately after the driver starts the engine of the work machine (step 1, hereinafter “step” is abbreviated as “S”). It is determined whether the remaining amount in the fuel tank is the same as or different from the remaining amount in the fuel tank when the operation of the work machine was stopped last time (S2). Here, if the remaining amount in the fuel tank at the time of starting the engine is the same as the previous remaining amount, the remaining amount is displayed from the remaining amount state stored when the operation of the work machine is stopped in S3 as described below. To start.

  On the other hand, when refueling or the like is performed when the operation of the work machine is stopped and the remaining amount in the fuel tank is changed from the state of the remaining amount at the previous stop of operation, first, the first float switch 5 is turned ON / OFF. The OFF state is confirmed (S4).

  At this time, if the first float switch 5 is ON, the remaining amount in the fuel tank is 2800 or more, so the remaining amount display on the display means 10 is set to “F (Full)” (S5). On the other hand, if the first float switch 5 is OFF, then the ON / OFF state of the second float switch 6 is confirmed (S13), and if the second float switch 6 is OFF, the third The ON / OFF state of the float switch 7 is confirmed (S22).

  Thereby, the remaining amount accommodated in the fuel tank at the time of starting the engine can be roughly confirmed and displayed on the display means 10. For example, when the first float switch 5 is OFF and the second float switch 6 is ON, it is confirmed that the remaining amount in the fuel tank is 2300 L or more, and the remaining amount is displayed on the display means 10. Set to "2300L" (S14). Thereafter, the ON / OFF state of the second float switch 6 is repeatedly confirmed (S15), and if it is determined that the second float switch 6 is OFF, the operations after S16 described below are performed. Is called.

  In addition, when the first and second float switches 5 and 6 are OFF and the third float switch 7 is ON, it is confirmed that the remaining amount in the fuel tank is 1800 L or more. The display of the remaining amount is set to “1800L” (S23). Thereafter, the ON / OFF state of the third float switch 7 is repeatedly confirmed (S24). If it is determined in S24 that the third float switch 7 has been turned OFF, the operations after S25 described below are performed.

  Further, when all of the first to third float switches 5, 6 and 7 are OFF, after the remaining amount display on the display means 10 is set to 1280L (S30), measurement of the remaining amount by the float sensor 4 is started. It is confirmed whether or not it is done (S31). At this time, if the measurement of the remaining amount by the float sensor 4 has not been started, the display of the remaining amount on the display means 10 is set to 1280L (S30). On the other hand, if the measurement of the remaining amount by the float sensor 4 has been started, the operations after S32 described below are performed.

  Next, when the remaining amount in the fuel tank is roughly checked as described above, the first float switch 5 is ON, and the remaining amount display on the display means 10 is set to “F (Full)”. The work after the combination (S5) will be described. In this case, until the first float switch 5 changes from ON to OFF, the display of the remaining amount on the display means 10 is set to “F (Full)” and the first float switch 5 is turned ON / OFF. The state is repeatedly confirmed (S6).

  Then, when the remaining amount in the fuel tank decreases as the work machine is driven, it is detected that the remaining amount in the fuel tank is 2800 L when the first float switch 5 changes from ON to OFF. Is done. At this time, the fuel remaining amount calculating means 8 receives the detection signal from the first float switch 5 and, for example, the fuel injection amount and fuel consumption data used in the fuel remaining amount calculating means 8 at the previous fuel remaining amount calculation. If data remains, delete those data.

  After it is determined in S6 that the first float switch 5 has changed from ON to OFF, engine fuel injection amount data is continuously output from the engine controller 9 in a short cycle of, for example, 0.1 seconds. The output fuel injection amount data is continuously input to the consumption amount calculation unit of the remaining fuel amount calculation means 8 (S7). Subsequently, the consumption amount calculation unit of the fuel remaining amount calculation means 8 receives the detection signal from the first float switch 5 and starts the calculation, and receives the detection signal based on the fuel injection amount data inputted. After that, the amount of fuel consumed in the fuel tank over time is calculated (S8). The value of the fuel consumption is, for example, a calculation formula of “Σ (fuel injection amount after the first float switch is turned off)”, and the fuel injection amount after the first float switch is turned off. It is possible to calculate by calculating the sum of.

  Thereafter, the remaining fuel amount calculation means 8 subtracts the fuel consumption amount calculated by the consumption amount calculation unit from the remaining fuel amount 2800L detected by the first float switch 5 in the remaining amount calculation unit. The calculated remaining amount in the fuel tank is calculated (S9). Thereby, it is possible to obtain a calculated remaining amount corresponding to the actual remaining amount actually stored in the fuel tank. The calculated remaining fuel amount data calculated by the remaining fuel amount calculating means 8 is continuously input from the remaining fuel amount calculating means 8 to the display means 10, whereby the remaining switch amount display portion of the display means 10. Is displayed (S10).

  Next, the ON / OFF state of the second float switch 6 is repeatedly confirmed (S11). If the second float switch 6 is in the ON state, the operations from S7 to S10 are repeated continuously. . Thereby, for example, in the switch remaining amount display portion of the display means 10 shown in FIG. 2, the calculated remaining amount calculated by the remaining fuel amount calculating means can be continuously displayed from the Full display to the 2300L display. The change in the remaining amount can be shown smoothly.

  In a construction machine, the oil level fluctuates in a short cycle due to intense rocking during operations such as turning. Therefore, it is necessary to perform filtering so that the remaining amount is not erroneously detected. That is, in the present embodiment, in the first float switch 5 and the second and third float switches 6 and 7 described below, the determination of the change of the switch from ON to OFF is performed for the float for 10 seconds. This can be done by comparing the ON time and OFF time of the switch. That is, when the OFF time of the float switch becomes longer than the ON time, that is, when the OFF time exceeds 5 seconds in 10 seconds, it can be determined that the float switch has been turned OFF.

  In some cases, after it is determined in S6 that the first float switch 5 is turned off, the float switch is turned on again for a long time, and it is confirmed that the switch is turned on. . At this time, the work is returned to S5, the remaining amount display on the display means 10 is again set to “F (Full)”, and the first float switch 5 is turned on until the first float switch 5 is turned off. Check / OFF repeatedly. The determination of ON / OFF in such a switch is the same in the second and third float switches 6 and 7.

  On the other hand, when the work machine is driven, the remaining amount in the fuel tank further decreases, and when it is determined in S11 that the second float switch is turned off, the remaining amount in the fuel tank is 2300L. It is detected that there is. When it is determined in S11 that the second float switch has been turned OFF, the remaining amount data output from the remaining fuel amount calculation means 8 to the display means 10 is switched, and the remaining amount display on the display means 10 is changed to the first display. 2 is adjusted to “2300L” detected by the float switch 6 (S12). At this time, when the fuel injection amount and fuel consumption data used in the operations of S7 to S10 remain in the remaining fuel amount calculation means 8, these data are deleted.

  The reason why the remaining amount display on the display means 10 is set to “2300L” in S12 is as follows. That is, for example, when the operations from S7 to S10 are repeated, the calculated remaining amount calculated by the fuel remaining amount calculating means 8 (that is, the remaining amount displayed on the display means) and the fuel tank An error may occur between a certain actual remaining amount. However, when it is determined in S11 that the second float switch 6 is turned off, in S12, the remaining amount display on the display means is set to “2300L”, so that the remaining amount display error can be reduced. By correcting, the actual remaining amount in the fuel tank can be matched with the remaining amount displayed on the display means. Thereby, the remaining amount in the fuel tank can be accurately displayed on the display means 10.

  After the remaining amount display is set to “2300L” in S12, the fuel injection amount data of the engine is input to the consumption amount calculating unit of the remaining fuel amount calculating means 8 in the same manner as the operations in S7 to 10 described above. The fuel consumption amount (= the fuel injection amount after the second float switch is turned off) is calculated by the consumption amount calculation unit based on the fuel injection amount data (S17). Next, a calculation is performed by subtracting the fuel consumption calculated by the consumption calculation unit from the remaining fuel amount 2300L detected by the second float switch 6 in the remaining amount calculation unit of the fuel remaining amount calculation means 8. The remaining amount is calculated (S18). Then, the calculated remaining amount calculated by the remaining fuel amount calculating means 8 is displayed on the switch remaining amount display section of the display means 10 (S19).

  Next, the ON / OFF state of the third float switch 7 is repeatedly confirmed (S20). If the third float switch 7 is ON, the operations from S16 to S19 are repeated continuously. . On the other hand, if it is determined in S20 that the third float switch 7 has been turned OFF, it is detected that the remaining amount in the fuel tank is 1800 L, and the remaining amount is displayed on the display means 10 as “ 1800L "(S21). Also at this time, if the fuel injection amount and fuel consumption data used in the operations of S16 to S19 remain, these data are deleted.

  After the remaining amount display is set to “1800L” in S21, the fuel injection amount data of the engine is input to the fuel remaining amount calculating means 8 in the same manner as the operations in S7 to 10 and S16 to 19 described above. The fuel consumption (= the fuel injection amount after the third float switch is turned off) is calculated based on the fuel injection amount data (S26). Next, the calculated remaining amount is calculated by subtracting the fuel consumption from the remaining amount of fuel 1800L detected by the third float switch 7 (S27). Then, the calculated remaining amount calculated by the remaining fuel amount calculating means 8 is displayed on the switch remaining amount display portion of the display means 10 (S28).

  Thereafter, until it is determined in S29 that the measurement of the remaining amount is started by the float sensor 4, that is, when the remaining amount in the fuel tank exceeds the reference amount, the above steps S25 to S28 are performed. Repeat the work continuously.

  On the other hand, when the remaining amount in the fuel tank decreases and it is determined in S29 that the remaining amount measurement by the float sensor 4 is started, that is, when the remaining amount in the fuel tank becomes less than the reference amount. Switches the remaining amount measuring means from the float switch to the float sensor, and measures the remaining amount by the float sensor 4 (S32). Then, the remaining amount in the fuel tank measured by the float sensor 4 is continuously displayed on the sensor remaining amount display portion of the display means 10 shown in FIG. 2, for example (S33).

  Further, according to the remaining amount display method of the present embodiment, whether or not the remaining amount in the fuel tank is equal to or less than a predetermined warning amount when the remaining amount in the fuel tank is in a range that is equal to or less than the reference amount. A determination can be made (S34), and an alarm can be output by the display means 10 when the remaining amount is below a predetermined warning amount (S35).

  For example, as described above, the warning amount is set to 186 L in advance, and an alarm such as “Empty” display 17 is output to the monitor 15 of the display means 10 when the remaining amount in the fuel tank becomes 186 L or less. . By outputting such an alarm, the driver operating the work machine knows that the fuel in the fuel tank is almost exhausted and recognizes that it is necessary to refuel the fuel tank. can do. Thereby, before the operation of the work machine stops due to running out of fuel, it is possible to rationally refuel at an appropriate time.

  Next, a case will be described in which it is determined immediately after the engine start (S1) of the working machine described above that the remaining amount in the fuel tank is the same as the previous remaining amount in S2. In this case, the remaining amount stored in the remaining fuel amount calculation means 8 when the work machine is stopped is displayed on the display means. At the same time, according to the stored remaining amount, if the remaining amount is 2800L or more, from S6 above, if the remaining amount is 2300L or more and less than 2800L, start from S7, if the remaining amount is 1800L or more and less than 2300L. From S16, if the remaining amount is more than 1280L and less than 1800L, the operation starts from S25, and if the remaining amount is 1280L or less, the operation starts from S32. Thereby, the remaining amount display can be appropriately performed from the remaining amount value stored at the time of the previous operation stop.

  According to the remaining amount display method of the present embodiment as described above, in the range where the remaining amount in the fuel tank is below the reference amount which is the upper limit of the remaining amount measurement range in the float sensor, the remaining amount is measured by the float sensor. Can be done accurately. By continuously displaying the measurement result of the remaining amount by the float sensor on the display means, it is possible to smoothly show how the remaining amount is decreasing. Thus, the driver can accurately check the remaining amount of fuel in real time without feeling uncomfortable with the remaining amount display on the display means, and can easily grasp the degree of fuel reduction.

  In the range where the remaining amount exceeds the predetermined reference amount, the remaining amount of fuel can be accurately detected step by step by the first to third float switches and displayed on the display means. Further, by subtracting the consumption calculated based on the fuel injection amount of the engine from the remaining amount detected by each of the first to third float switches, a change in the remaining amount that cannot be detected by the float switch is obtained by calculation. , Can be continuously displayed on the display means.

  Thereby, when the display means displays the remaining amount as shown in FIG. 2, for example, the remaining amount display error is corrected at each point of the F display, the 2300L display, and the 1800L display, so that the actual remaining amount in the fuel tank is displayed. The quantity can be accurately displayed by the display means. Furthermore, the change in the remaining amount from the F display to the 2300L display, the change in the remaining amount from the 2300L display to the 1800L display, and the change in the remaining amount from the 1800L display to the 1280L display can be smoothly shown.

  In the present invention, at least one float switch may be provided in the fuel tank. However, by detecting the remaining amount of fuel step by step with the first to third float switches as described above. The error of the remaining amount display can be corrected at three points where the float switch is installed. Thereby, the display means can display the remaining amount in the range exceeding the reference amount more accurately.

  That is, according to the present invention, when displaying the remaining amount of fuel stored in the large-capacity type fuel tank, the remaining amount is displayed on the display means from the state where the remaining amount in the fuel tank is full. It is possible to carry out appropriately and smoothly over all the states up to the empty state. In addition, the remaining amount of fuel in the low remaining amount region where the remaining amount is less than the reference amount can be displayed very accurately, while the remaining amount of fuel in the region where the remaining amount exceeds the reference amount can be displayed reasonably accurately. Therefore, the reliability of the remaining amount display can be improved. Further, according to the present invention, it is not necessary to install a plurality of float sensors in the fuel tank, and it is not necessary to use ultrasonic waves or laser light, so that the remaining amount can be displayed with a simple system.

  In the present invention, when refueling the work machine, if the remaining amount after refueling obtained by summing the refueling amount and the remaining amount in the fuel tank before refueling is accurately known, For example, when the engine is started, the remaining amount after refueling can be input to the fuel remaining amount calculating means 8 and displayed on the display means 10. If the remaining amount after refueling is input to the remaining fuel amount calculation means 8 in this way, for example, the operation of roughly checking the remaining amount as described above can be omitted. Further, the fuel remaining amount calculating means 8 calculates the remaining amount in the fuel tank by subtracting the fuel consumption from the inputted remaining amount after refueling. The remaining amount can be accurately displayed in real time. Further, if the scale of the monitor is changed so that the remaining amount can be displayed from 3200L on the display means 10, for example, even if the remaining amount in the fuel tank is 2800L or more, the remaining amount is accurately displayed on the display means. Can also be displayed.

  Furthermore, although the case where the fuel tank is provided with three float switches is taken as an example in the above description, the present invention is not limited to this. For example, only one float switch can be installed in the fuel tank, and two, four, or more float switches can be installed in consideration of installation space and cost. Further, in the above description, a case where the remaining amount measured by the float sensor 4 is once output to the fuel remaining amount calculating means 8 and then output to the display means 10 for display is described. For example, the remaining amount measured by the float sensor 4 is measured. The remaining amount can be directly output to the display means 10 and displayed.

  The present invention can be effectively applied to a display of the remaining amount of fuel stored in a large-capacity fuel tank in a working machine such as a hydraulic excavator.

It is a mimetic diagram showing typically the composition of the fuel residual quantity display system concerning the present invention. It is a figure which shows an example of the specific aspect of a display means roughly. It is a flowchart which shows an example of the residual amount display method which concerns on this invention. It is a schematic diagram which represents typically the structure of a float sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Remaining quantity display system 2 Fuel tank 3 Fuel 4 Float sensor 5 1st float switch 6 2nd float switch 7 3rd float switch 8 Fuel residual quantity calculation means 9 Engine controller 10 Display means 11 Variable resistor 12 Arm 13 Float 15 Monitor 16 Needle 17 “Empty” display 20 Float sensor 21 Variable resistor 22 Arm 23 Float

Claims (8)

A remaining amount display system that measures and displays the remaining amount of fuel in a large-capacity fuel tank,
In a range where the remaining amount in the fuel tank is a predetermined reference amount or less, a float sensor for measuring the remaining amount;
In the range where the remaining amount in the fuel tank exceeds the reference amount, at least one float switch for detecting the remaining amount;
A display unit having a sensor remaining amount display unit for displaying a remaining amount obtained by the float sensor and a switch remaining amount display unit for displaying a remaining amount obtained by the float switch;
A remaining amount display system characterized by comprising:   2. The remaining amount display system according to claim 1, wherein the float switch is provided in multiple stages at different height positions of the fuel tank, and detects the remaining amount in the fuel tank in multiple stages. . When the detection signal from the float switch is received, the calculation is started, and a consumption calculation unit that calculates the consumption of fuel in the fuel tank with the passage of time after receiving the detection signal and the float switch detects A fuel remaining amount calculating means having a remaining amount calculating unit for subtracting the consumption calculated by the consumption calculating unit from the remaining amount and calculating the remaining amount in the fuel tank,
3. The remaining amount display according to claim 1, wherein the remaining amount in the fuel tank obtained by the remaining fuel amount calculating means is continuously displayed on a switch remaining amount display portion of the display means. system. An engine controller for controlling a fuel injection amount of an engine that consumes fuel in the fuel tank;
4. The remaining amount display system according to claim 3, wherein the consumption calculation unit calculates the consumption based on fuel injection amount data output from the engine controller.   5. The remaining amount display system according to claim 1, wherein the display means outputs an alarm when the remaining amount in the fuel tank becomes a predetermined warning amount or less. A remaining amount display method for measuring and displaying the remaining amount of fuel in a large-capacity fuel tank,
Detecting the remaining amount with at least one float switch when the remaining amount in the fuel tank is equal to or greater than a predetermined reference amount;
Measuring the remaining amount with a float sensor when the remaining amount in the fuel tank is less than or equal to the reference amount;
A remaining amount display method comprising displaying on a display means a remaining amount obtained by the float switch and a remaining amount obtained by the float sensor.   7. The remaining amount according to claim 6, comprising detecting the remaining amount in the fuel tank in multiple stages by the float switches provided in multiple stages at different height positions of the fuel tank. Display method. Calculation when receiving a detection signal from the float switch, and calculating the amount of fuel consumed in the fuel tank over time after receiving the detection signal by the calculation;
Subtracting the calculated consumption from the remaining amount detected by the float switch to calculate the remaining amount in the fuel tank;
The remaining amount display method according to claim 6 or 7, further comprising continuously displaying the calculated remaining amount in the fuel tank on the display means.

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